This invention relates generally to an apparatus and process for the introduction of additives into a polymer flake flow stream. More particularly, it relates to the uniform introduction of additives to the polymer flake prior to its being processed in a melt extruder.
Thermoplastic polymers are-often treated with additives in the molten state by the addition of additive concentrates. Such concentrates are concentrated dispersions of an additive in a carrier polymer, the carrier polymer being either the same as or compatible with the polymer to be treated. There are several known methods for adding a concentrate to a thermoplastic polymer.
One method is to meter a pelletized concentrate into the throat of a polymer extruder using either volumetric or gravimetric pellet feeders.